sysdeps/unix/sysv/linux/posix_fadvise64.c

   1 /* Copyright (C) 2003-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <fcntl.h>
  20 #include <shlib-compat.h>
  21
  22 int __posix_fadvise64_l64 (int fd, off64_t offset, off64_t len, int advise);
  23 libc_hidden_proto (__posix_fadvise64_l64)
  24
  25 /* Both arm and powerpc implements fadvise64_64 with last 'advise' argument
  26    just after 'fd' to avoid the requirement of implementing 7-arg syscalls.
  27    ARM also defines __NR_fadvise64_64 as __NR_arm_fadvise64_64.
  28
  29    tile requires __ASSUME_ALIGNED_REGISTER_PAIRS but implements the 32-bit
  30    fadvise64_64 without the padding 0 after fd.
  31
  32    s390 implements fadvice64_64 using a specific struct with arguments
  33    packed inside.  This is the only implementation handled in arch-specific
  34    code.  */
  35
  36 #ifdef __ASSUME_FADVISE64_64_NO_ALIGN
  37 # undef __ALIGNMENT_ARG
  38 # define __ALIGNMENT_ARG
  39 #endif
  40
  41 #ifndef __NR_fadvise64_64
  42 # define __NR_fadvise64_64 __NR_fadvise64
  43 #endif
  44
  45 /* Advice the system about the expected behaviour of the application with
  46    respect to the file associated with FD.  */
  47
  48 int
  49 __posix_fadvise64_l64 (int fd, off64_t offset, off64_t len, int advise)
  50 {
  51   INTERNAL_SYSCALL_DECL (err);
  52 #ifdef __ASSUME_FADVISE64_64_6ARG
  53   int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd, advise,
  54                                    SYSCALL_LL64 (offset), SYSCALL_LL64 (len));
  55 #else
  56   int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd,
  57                                    __ALIGNMENT_ARG SYSCALL_LL64 (offset),
  58                                    SYSCALL_LL64 (len), advise);
  59 #endif
  60   if (!INTERNAL_SYSCALL_ERROR_P (ret, err))
  61     return 0;
  62   return INTERNAL_SYSCALL_ERRNO (ret, err);
  63 }
  64
  65 /* The type of the len argument was changed from size_t to off_t in
  66    POSIX.1-2003 TC1.  */
  67 #ifndef __OFF_T_MATCHES_OFF64_T
  68 # if SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3)
  69 int __posix_fadvise64_l32 (int fd, off64_t offset, size_t len, int advise);
  70
  71 int
  72 attribute_compat_text_section
  73 __posix_fadvise64_l32 (int fd, off64_t offset, size_t len, int advise)
  74 {
  75   return __posix_fadvise64_l64 (fd, offset, len, advise);
  76 }
  77
  78 versioned_symbol (libc, __posix_fadvise64_l64, posix_fadvise64, GLIBC_2_3_3);
  79 compat_symbol (libc, __posix_fadvise64_l32, posix_fadvise64, GLIBC_2_2);
  80 # else
  81 weak_alias (__posix_fadvise64_l64, posix_fadvise64);
  82 # endif
  83 #else
  84 weak_alias (__posix_fadvise64_l64, posix_fadvise64);
  85 strong_alias (__posix_fadvise64_l64, posix_fadvise);
  86 #endif
  87 libc_hidden_def (__posix_fadvise64_l64)